Move staging value application logic to persistent_properties and add
unit tests
1, Previous implementation has the staged prop application done in
property_service, which caused a number of unnecessary changes which
including exposing apis like AddPersistentProperty. In addition, it made
the property_service logic complicated. A better design is to have the
staged value application done while reading the persistent properties
from file. This way, no change to property service. In addition, unit
test is much cleaner and efficient.
2, add a unit test to lock down the behavior. Specifically, it locks down that when a prop is staged, it should be applied the next time when the persistent prop is loaded. In addition, it should lock down that other persistent props are not overwritten.
Bug: b/307752841, b/300111812, b/306062513
Change-Id: I43c603efbb803195065dda3f0bc2145716302bbc
diff --git a/init/persistent_properties.cpp b/init/persistent_properties.cpp
index e89244f..6f8a4de 100644
--- a/init/persistent_properties.cpp
+++ b/init/persistent_properties.cpp
@@ -46,6 +46,13 @@
constexpr const char kLegacyPersistentPropertyDir[] = "/data/property";
+void AddPersistentProperty(const std::string& name, const std::string& value,
+ PersistentProperties* persistent_properties) {
+ auto persistent_property_record = persistent_properties->add_properties();
+ persistent_property_record->set_name(name);
+ persistent_property_record->set_value(value);
+}
+
Result<PersistentProperties> LoadLegacyPersistentProperties() {
std::unique_ptr<DIR, decltype(&closedir)> dir(opendir(kLegacyPersistentPropertyDir), closedir);
if (!dir) {
@@ -146,13 +153,6 @@
} // namespace
-void AddPersistentProperty(const std::string& name, const std::string& value,
- PersistentProperties* persistent_properties) {
- auto persistent_property_record = persistent_properties->add_properties();
- persistent_property_record->set_name(name);
- persistent_property_record->set_value(value);
-}
-
Result<PersistentProperties> LoadPersistentPropertyFile() {
auto file_contents = ReadPersistentPropertyFile();
if (!file_contents.ok()) return file_contents.error();
@@ -266,8 +266,57 @@
}
}
- return *persistent_properties;
+ // loop over to find all staged props
+ auto const staged_prefix = std::string_view("next_boot.");
+ auto staged_props = std::unordered_map<std::string, std::string>();
+ for (const auto& property_record : persistent_properties->properties()) {
+ auto const& prop_name = property_record.name();
+ auto const& prop_value = property_record.value();
+ if (StartsWith(prop_name, staged_prefix)) {
+ auto actual_prop_name = prop_name.substr(staged_prefix.size());
+ staged_props[actual_prop_name] = prop_value;
+ }
+ }
+
+ if (staged_props.empty()) {
+ return *persistent_properties;
+ }
+
+ // if has staging, apply staging and perserve the original prop order
+ PersistentProperties updated_persistent_properties;
+ for (const auto& property_record : persistent_properties->properties()) {
+ auto const& prop_name = property_record.name();
+ auto const& prop_value = property_record.value();
+
+ // don't include staged props anymore
+ if (StartsWith(prop_name, staged_prefix)) {
+ continue;
+ }
+
+ auto iter = staged_props.find(prop_name);
+ if (iter != staged_props.end()) {
+ AddPersistentProperty(prop_name, iter->second, &updated_persistent_properties);
+ staged_props.erase(iter);
+ } else {
+ AddPersistentProperty(prop_name, prop_value, &updated_persistent_properties);
+ }
+ }
+
+ // add any additional staged props
+ for (auto const& [prop_name, prop_value] : staged_props) {
+ AddPersistentProperty(prop_name, prop_value, &updated_persistent_properties);
+ }
+
+ // write current updated persist prop file
+ auto result = WritePersistentPropertyFile(updated_persistent_properties);
+ if (!result.ok()) {
+ LOG(ERROR) << "Could not store persistent property: " << result.error();
+ }
+
+ return updated_persistent_properties;
}
+
+
} // namespace init
} // namespace android